Resin Flow, Symptom Development, and Lignin Biosynthesis of Two Pine Species in Response to Wounding and Inoculation with Fusarium circinatum

Abstract

Resin flow, symptom development, and lignin biosynthesis in response to wounding and fungal inoculation were investigated in Pinus rigida and Pinus densiflora. The two-year-old seedling stems were subjected to three types of treatments: (i) wounding without inoculation, (ii) wound-inoculation with a conidial suspension of Fusarium circinatum, and (iii) pre-wounding woundinoculation with the fungus 20 days after the initial wounding. Resin flow from wounding sites was more evident in P. rigida than P. densiflora in all treatments. The wound-inoculation with the fungus induced almost two-fold higher levels of resin flow than the other treatments in both species. The pre-wounding woundinoculation appeared to result in a decrease in pitch canker development in the two pine species. Some reductions in disease severity were observed in the prewounding wound-inoculated P. rigida, showing a mean disease severity of less than 85%, compared with approximately 100% in the wound-inoculated stems. Disease severity was approximately 50% in the woundinoculated P. densiflora, whereas 10% in the pre-wounding wound-inoculated stems. Higher amounts of lignin were found from bark (ca. 40%) than from xylem (ca. 30%). The wound-inoculated bark and the pre-wounding wound-inoculated bark exhibited higher amounts of lignin among the other treatments. These results suggest that the wound-inoculation apparently prompt the increase in resin flow and lignin biosynthesis from the two pine species, and the prior wounding may be involved in decreased disease severity against the further invasion of F. circinatum.

Evaluating methyl jasmonate for induction of resistance to Fusarium oxysporum, F. circinatum and Ophiostoma novo-ulmi

“…Elicitor compounds affect the synthesis of chemical compounds in plants, but this will result in constraints in carbon allocation and ultimately with reduce plant Evaluating methyl jasmonate for induction of resistance growth or even stop the shoot elongation after the elicitor treatment (Heijari et al, 2005), as observed here. MeJA increased the resin duct density of our seedlings, but despite the general effectiveness of traumatic ducts to contain and reduce damages caused by insects and pathogens (Phillips and Croteau, 1999), F. circinatum is able to tolerate the resin and even stimulate its production on pine trees (Davis et al, 2002;Kim et al, 2010). Thus, even if an increase of resin duct density was observed, F. circinatum would be able to surpass this inducible defense strategy.…”

“…Such interaction may be especially evident in young seedlings where growth during an early establishment phase is likely to be an important component of competitive ability. Resin production is the most familiar and visible component of pine defense (Davis et al, 2002;Kim et al, 2010). It was recently observed that the relative resin production of P. nigra was much lower in 1-than in 2-year-old seedlings, suggesting that the younger trees allocated a lower proportion of the carbon budget to resin synthesis (Wainhouse et al, 2009).…”

“…El MeJA no protegió a las semillas ni a las plántulas de P. pinaster ante F. oxysporum, quizá debido a que las plántulas eran demasiado jóvenes para inducir los mecanismos fisiológicos responsables de la resistencia. Basándonos en los cambios morfológicos observados en las plántulas de 6 meses de P. pinaster (reducción del creci-2010; Kim et al, 2010). Worldwide, damping off caused by Fusarium oxysporum is probably one the most severe disease affecting seedlings in forest nurseries (Machón et al, 2006).…”

Factores anatómicos, dendrométricos y climáticos implicados en la producción de resina de Pinus pinaster AIT. : aplicación a la mejora de los métodos de resinación

“…Este género, al presentar la red constitutiva de canales descrita con tan alta complejidad y densidad, parece menos propenso a la inversión energética en estructuras defensivas de tipo inducido a diferencia de otras coníferas Nagy et al, 2006;. Cabe sin embargo destacar que la mayor parte de trabajos sobre la inducción de canales traumáticos en pinos se ha llevado a cabo en condiciones que distan mucho de las presentes en un aprovechamiento resinero, es decir, sobre plántula Kim et al, 2010), con heridas pequeñas o realizadas en periodos de tiempo muy breve , o evaluando el resultado a muy corto plazo y tan solo en la región más próxima a la herida (Oven & Torelli, 1999;Nagy et al, 2006). En el presente trabajo se analizan los efectos de la herida de resinación real, en árboles adultos, en un marco temporal de varios años y en distintas localizaciones en el fuste, permitiendo con todo ello una visión más ajustada a los efectos de este tipo de lesión en una masa puesta en resinación.…”

“…The socioeconomic importance of tapping has prompted wide scientific research to increase production by studying the resin secretion structures , the influence of the tapping wound on oleoresin secretion , the application of chemical stimulants or fertilizers , modeling of resin yield and the development of breeding programs . The role of resin flow as constitutive and induced defense against pests and disease has also been extensively explored (Berryman, 1972;Kim et al, 2010).…”